Laurell, Fredrik

Abstract [en]

The use of periodically poled KTiOPO4 as a gain medium in efficient nanosecond optical parametric oscillators pumped by a flash-lamp-pumped 𝑄‐switched Nd:YAG laser is demonstrated. Parametric radiation in the 1.8–2.5‐µm spectral region was achieved when the crystal temperature was tuned from 10 to 100 °C. A maximum total output energy of 1.8 mJ was obtained at a pump level of 3.5 mJ. Stable operation was achieved, with conversion efficiencies reaching 50%. No gray tracking or laser damage was observed, even for pump intensities of 450 MW/cm2.